npc vibrating in sexlab

[Farinata of Oblivion]

for some strange reason female npc's have started shaking rapidly during sex animations, I haven't changed anything about the instillation or mod order in skyrim so I'm unclear on how to proceed in rectifying it. 

Its very distracting. 

[myuhinny]

Are they still the same distance away? I have seen it before where they get a certain distance and they start bouncing. Uneven terrain can also cause it. 

[Farinata of Oblivion]

They are usually right next to me when I initiate the animation, also it was in doors so the terrine should have been even.